|The biogeochemistry of microbial mats, stromatolites and the ancient biosphere - Desmarais, D. J.|
Stromatolites offer an unparalleled geologic record of early life, because they constitute the oldest and most abundant recognizable remains of microbial ecosystems. Microbial mats are living homologs of stromatolites; thus, the physiology of the microbiota as well as the processes which create those features of mats (e.g., biomarker organic compounds, elemental and stable isotopic compositions) which are preserved in the ancient record...
Keywords: BIOLOGICAL EVOLUTION; ECOSYSTEMS; MOLECULAR BIOLOGY; PROKARYOTES; RADIATION EFFECTS; STERILIZATION; HEURISTIC METHODS; MODELS
|Multi-Center Traffic Management Advisor Operational Field Test Results - Farley, Todd|
The Multi-Center Traffic Management Advisor (McTMA) is a research prototype system which seeks to bring time-based metering into the mainstream of air traffic control (ATC) operations. Time-based metering is an efficient alternative to traditional air traffic management techniques such as distance-based spacing (miles-in-trail spacing) and managed arrival reservoirs (airborne holding). While time-based metering has demonstrated significant benefit in terms of arrival throughput and arrival delay...
Keywords: BACTERIA; MOISTURE CONTENT; MICROSCOPY; INFRARED RADIATION; IMAGE ANALYSIS; HETEROTROPHS; PROKARYOTES; FLUORESCENCE; CHLOROPHYLLS; AEROBES; PHOTICS
|Communication by Fire (and Smoke) Signals in the Kingdom of Judah - Borowski, Oded|
This paper examines the use of ancient fire and smoke signals for communication in the Kingdom of Judah. Historical and biblical references are cited that discuss this communication system. The current physical and political landscape of Israel precludes testing of hypotheses using traditional techniques. The use of a GIS is enlisted to overcome these obstacles and predict line-of-sight patterns that are conducive for a fire signal communication system...
Keywords: SCANNING ELECTRON MICROSCOPY; PHOSPHATES; PROKARYOTES; MICROORGANISMS; MICROSTRUCTURE; CARBONACEOUS CHONDRITES; METEORITES; FOSSILS; EXOBIOLOGY; SPECTROSCOPY; SHALES
|The NASA SETI program - Billingham, J.|
In 1959, it was proposed that a sensible way to conduct interstellar communication would be to use radio at or near the frequency of hydrogen. In 1960, the first Search for Extraterrestrial Intelligence (SETI) was conducted using a radiotelescope at Green Bank in West Virginia. Since 1970, NASA has systematically developed a definitive program to conduct a sophisticated search for evidence of extraterrestrial intelligent life...
Keywords: AUSTRALIA; GEOCHRONOLOGY; STRATIGRAPHY; BASALT; FILAMENTS; FOSSILS; PALEOBIOLOGY; PRECAMBRIAN PERIOD; PROKARYOTES; QUARTZ; BIOGENY
|NASA-SETI microwave observing project: Targeted Search Element (TSE) - Webster, L. D|
The Targeted Search Element (TSE) performs one of two complimentary search strategies of the NASA-SETI Microwave Observing Project (MOP): the targeted search. The principle objective of the targeted search strategy is to scan the microwave window between the frequencies of one and three gigahertz for narrowband microwave emissions eminating from the direction of 773 specifically targeted stars. The scanning process is accomplished at a minimum resolution of one or two Hertz at very high sensitiv...
Keywords: ECOLOGY; CARBONATES; PLANKTON; PROKARYOTES; SEDIMENTS; SHALES; SHOALS; FOSSILS; LAGOONS; MICROORGANISMS; PALEOBIOLOGY; PRECAMBRIAN PERIOD; STRATIGRAPHY; TIDAL FLATS; BIOLOGICAL EVOLUTION
|Symbiosis and the origin of eukaryotic motility - Margulis, L.|
Ongoing work to test the hypothesis of the origin of eukaryotic cell organelles by microbial symbioses is discussed. Because of the widespread acceptance of the serial endosymbiotic theory (SET) of the origin of plastids and mitochondria, the idea of the symbiotic origin of the centrioles and axonemes for spirochete bacteria motility symbiosis was tested. Intracellular microtubular systems are purported to derive from symbiotic associations between ancestral eukaryotic cells and motile bacteria...
Keywords: BACTERIA; METHYLATION; MICROORGANISMS; MODULATION; MOLECULES; OXYGEN; BIOLOGICAL EVOLUTION; FATTY ACIDS; GAS EVOLUTION; LIPIDS; MEMBRANES; PROKARYOTES; SYNTHESIS (CHEMISTRY); AUGMENTATION
|Chemolithotrophy and physiology of bacterial nutrient limitation - Matin, A|
An overview of the physiology of chemolithotrophic bacteria, particularly the thiobacilli, was presented. In these bacteria unique physiological traits are expressed during nutrient limited growth. Different physiological types of chemolithotrophs, pathways of sulfur oxidation, and electron transport in the thiobacilli, problems encountered by chemolithotrophs in the generation of reducing power, and some explanations of the phenomenon of obligate chemolithotrophy were considered...
Keywords: AEROBES; AMINO ACIDS; ARCHAEBACTERIA; EUKARYOTES; PHOTOSYNTHESIS; PROKARYOTES; REDUCTION (CHEMISTRY); BACTERIA; BIOCONVERSION; GLUTATHIONE; HYPEROXIA; ORGANIC COMPOUNDS; OXYGEN; THIOLS; TOXICITY
|Microbiology of solar salt ponds - Javor, B|
Solar salt ponds are shallow ponds of brines that range in salinity from that of normal seawater (3.4 percent) through NaCl saturation. Some salterns evaporate brines to the potash stage of concentration (bitterns). All the brines (except the bitterns, which are devoid of life) harbor high concentrations of microorganisms. The high concentrations of microorganisms and their adaptation to life in the salt pond are discussed.
Keywords: GEOCHRONOLOGY; PROKARYOTES; STRUCTURAL PROPERTIES (GEOLOGY); SULFUR; GEODYNAMICS; GEOMORPHOLOGY; PALEOBIOLOGY; PALEONTOLOGY; PRECAMBRIAN PERIOD; ROCK MECHANICS; FOSSILS; PLANETARY ENVIRONMENTS
|Launchpad: Methane - An Indicator for Life? (Methane4) - NASA eClips|
See how scientists are using spectroscopy to identify methane plumes on Mars. Learn about the biological and geological processes that form methane on Earth and the implications for astrobiologists who are looking for life beyond Earth.
Keywords: NASA; NASA eClips; NIA; Launchpad; secondary; video; education; engineering; technology; science; life; astrobiology; decay; methane; methanogens; extremolphiles; microbes; organics; spectroscopy; atmosphere; Mars Science Laboratory; Curiosity; prokaryotes; biology; geology; light
|OCW Scholar: Fundamentals of Biology|
Instructor: Dr. Michelle Mischke This collection contains clips from lecture videos of MIT's Introduction to Biology classes. Each video will show the instructor explaining a concept that is covered in the session of the Fundamentals of Biology. View the complete course: http://ocw.mit.edu/7-01SCF11
Keywords: Mendel; Mendel's laws; pea plants; experiments; inherited traits; controls; gene; allele; genotype; heterozygote; homozygote; phenotype; dominant; recessive; independent assortment; round; wrinkled; green; yellow; true-breeding; cytology; chromosomes; drosophila; levels of organization; biosphere; ecosystem; organism; organ; tissues; cells; organelles; molecules; nucleated cells; prokaryotes; eukaryotes; heredity; transforming principle; Griffiths; Pneumoccocus bacteria; virulent; Avery; McCarty; McLeod; DNA; adenine; guanine; thymine; cytosine; deoxyribose; polymerization; Hershey-Chase; bacterial viruses; Watson; Crick; Franklin; x-ray crystallography; double helix; Meselson and Stahl; semi-conservative replication; semi-conservative replication model; DNA; 14N; 15N density centrifugation; DNA Replication; enzyme; bacterial cells; assay; 5'; 3'; primer; nucleotides; DNA Polymerase; primase; ligase; topo isomerase; topological problem; fidelity of replication; cloning; purification; vector; transformation